The present invention relates to a device for the calculation of the geometrical characteristics of rectangles, namely:- The ratio of the lengths of the contiguous sides of the rectangle, the lengths of its sides, the length of its diagonal and its surface area.
This device is intended to execute the framing of rectangles or possibly squares of predetermined dimensions on documents or various objects such as photographs and drawings etc., and is usable especially in photography, architecture, industrial design, decoration, etc.